Ultrasonographic Anomalies Research Articles

Abnormal nuchal findings on screening ultrasonography: Aneuploidy stratification on the basis of ultrasonographic anomaly and gestational age at detection

OBJECTIVE: Our purpose was to determine the specific likelihood of different aneuploidies by gestational age in patients with nuchal folds and simple and septated nuchal membranes. STUDY DESIGN: Retrospective database analysis was performed of 158 consecutive patients with a nuchal fold or simple or septated nuchal membrane on either abdominal or vaginal ultrasonography. RESULTS: Thirty-eight patients with nuchal folds, 65 with simple nuchal membranes, and 55 with septated nuchal membranes were evaluated. Septated nuchal membranes were associated with the highest incidence of karyotypic abnormalities (>50%). A peak incidence of trisomy 21 (27%) was found in the early midtrimester, leveling off to 11% by the late midtrimester. The late first trimester had a high incidence of trisomy 18 (22%), occurring more frequently than 45,X. CONCLUSION: Ultrasonographic anomalies in the posterior neck are associated with aneuploidy from 21% to 58% of the patients in this selected population. Each anomaly has different risks for aneuploidy type, varying with gestational age at diagnosis. (Am J Obstet Gynecol 1996;175:995-9.)

Fetal lateral ventricle choroid plexus cysts: The dilemma of amniocentesis

Although lateral ventricle choroid plexus cysts in the second-trimester fetus have been considered a benign developmental phenomenon of no clinical significance, an association with trisomy 18 has been suggested. We designed a prospective study to determine whether karyotype analysis is indicated when such cysts are encountered on prenatal sonogram. During a 20-month period, 5400 low-risk pregnant women were examined sonographically in the second trimester to evaluate the prevalence of fetal lateral ventricle choroid plexus cysts and the incidence of ultrasonographic anomalies associated with such cysts in fetuses with trisomy 18 referred from cytogenetic laboratories. Thirty cases of fetal lateral ventricle choroid plexus cysts (0.6%) were detected during the study period; 28 newborns were normal and two had trisomy 18. One of the affected infants had other associated ultrasonographic abnormalities suggesting aneuploidy, whereas no detectable abnormalities could be found in the other. Three other pregnant women were referred to us from the cytogenetics services because fetal karyotype revealed trisomy 18; in all three cases lateral ventricle choroid plexus cysts and other sonographic abnormalities were observed. In total, we scanned five fetuses with trisomy 18, of which all had lateral ventricle choroid plexus cysts and four had associated detectable anomalies. We could not find any association between cyst size, number, or laterality and trisomy 18. In addition to the five cases of trisomy 18 described, we found 33 other fetuses reported with trisomy 18 in the second trimester; of this total, 25 (66%) had lateral ventricle choroid plexus cysts and 30% had no other detectable abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)